Fix unquoted database name

[skion]

resolves #900

Description & motivation

This fixes get_relations_by_prefix() when the database name contains e.g. a hyphen on Postgres.

Checklist

• This code is associated with an Issue which has been triaged and accepted for development.
• I have verified that these changes work locally on the following warehouses (Note: it's okay if you do not have access to all warehouses, this helps us understand what has been covered)
  • BigQuery
  • Postgres
  • Redshift
  • Snowflake
• I have updated the README.md (if applicable)
• I have added tests & descriptions to my models (and macros if applicable)

[dbeatty10]

Thanks for putting this together @skion !

Taking an initial look, your proposal is simple and aligns with all the other macros. Ideally, we'd add a test case that includes a "mIxEdCaSe" database name so that we can validate that all the data warehouse we test work in this scenario (and also to prevent regressions in the future). But that might prove to be a bit tricky / impractical. So we might need to fall back on some manual testing for this. I'm doing to do some manual testing with Postgres, Snowflake, and Databricks both with and without the changes in your PR. I'll report back later with those results.

[skion]

Any luck on this @dbeatty10 ?